频变输电线路模型中的低阶拟合方法

发布时间：2018-09-06 08:40

【摘要】：对特征阻抗和传播系数的有理函数拟合是考虑参数频变的输电线路建模中的关键步骤。传统的模域输电线路模型采用的Bode渐近线拟合法会产生大量零极点,其中一部分对提高模型精度没有作用并会导致电磁暂态仿真中产生不必要的计算。为避免冗余零极点的产生,提出了一种应用于频变输电线路模型中的低阶有理函数拟合方法。首先对线路特征阻抗和传播系数进行低阶零极点定位,然后用非线性最小二乘法提高拟合精度,从而实现对特征阻抗和传播系数的低阶有理函数拟合。对比Bode渐近线法的拟合结果,低阶拟合方法能够在保证拟合精度的同时降低拟合函数的阶数,从而提高电磁暂态计算效率。
[Abstract]:The rational function fitting of characteristic impedance and propagation coefficient is a key step in the modeling of transmission line considering the frequency variation of parameters. The Bode asymptote fitting method used in the traditional mode domain transmission line model will produce a large number of zeros and poles, some of which will not improve the accuracy of the model and lead to unnecessary calculation in electromagnetic transient simulation. In order to avoid the occurrence of redundant zeros and poles, a low order rational function fitting method applied to the FVT transmission line model is proposed. First, the line characteristic impedance and propagation coefficient are located at low order zero poles, then the fitting accuracy is improved by nonlinear least square method, so that the low order rational function fitting of characteristic impedance and propagation coefficient is realized. Compared with the fitting results of Bode asymptote method, the low order fitting method can reduce the order of the fitting function while ensuring the fitting accuracy, thus improving the efficiency of electromagnetic transient calculation.
【作者单位】：电力设备电气绝缘国家重点实验室(西安交通大学);国网陕西省电力公司经济技术研究院;中国电力科学研究院;
【基金】：国家自然科学基金项目(51507126) 国家电网公司基础性前瞻项目“大规模交直流电力系统全电磁暂态仿真理论方法研究”~~
【分类号】：TM75;TM743

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